I think iPhoto and Aperture use the same raw developer. But iphoto is pretty basic in terms of other photo editing tools.. I use in emergency on my Air when I dont have my MacBook about.

Having tried CaptureOne .. if I didn't have Aperture already I would go for that. Aperture does nice job but there was something better, richer deeper colour in the C1. Also I get feeling C1 will update its software plus its raw capability re Fuji new models faster than Aperture. I am not against Aperture but it was a bloody long wait before it would handle RAF files.